In Brazil's semiarid region, rainfall patterns are an important factor for
the success of rain-fed agriculture. Erratic and uneven rainfall is the main cause
of crop losses. The traditional planting system in the semiarid region is pit
seeding in a level surface, using a hoe, forming a little pit capable of catching
and storing a limited amount of water. Apparently, this system seems to cause
no harm to the environment. However, since the soil has not been ploughed, its
surface becomes slightly compacted, making infiltration more difficult and run-off
easier. Therefore "in situ" rainwater catchments are more suitable to
the existing planting systems and they can be implemented with the help of machines
or animals. The most used "in situ" rainwater catching practices in
Brazil's semiarid region are: pre- and post-seeding furrowing, stopped furrows,
W system, partial plowing and the Guimarães Duque system. The more suitable rainwater
collection systems for semiarid farming conditions are presented in this paper.